The goal of this study are to: 1) calculate the incidence of EP in a population of inner city women, 2) identify the risk factors for EP, and 3) identify factors predictive of EP in the subgroup of pregnant women who present to an emergency department, but are discharged without a definitive diagnosis and derive a clinical prediction rule to help identify those at highest risk for EP in an attempt to shorten the time needed for diagnosis of women with EP.